A multi-centre randomised double-blind placebo-controlled trial to evaluate the value of a single bolus intravenous alfentanil in CT colonography
1 Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1100 DD, the Netherlands
2 Department of Anaesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam 1100 DD, the Netherlands
3 Department of Radiology, Onze Lieve Vrouwe Gasthuis, Amsterdam 1091 AC, the Netherlands
BMC Gastroenterology 2013, 13:94 doi:10.1186/1471-230X-13-94Published: 25 May 2013
Pain is common during colonic insufflation required for CT colonography. We therefore evaluate whether a single intravenous alfentanil bolus has a clinically relevant analgesic effect compared with placebo in patients undergoing CT colonography.
A prospective multi-centre randomised double-blind placebo-controlled trial was performed in patients scheduled for elective CT colonography. Patients were randomised to receive either a bolus of 7.5 μg/kg alfentanil (n = 45) or placebo (n = 45). The primary outcome was the difference in maximum pain during colonic insufflation on an 11-point numeric rating scale. We defined a clinically relevant effect as a maximum pain reduction of at least 1.3 points. Secondary outcomes included total pain and burden of CT colonography (5-point scale), the most burdensome aspect and side effects. Our primary outcome was tested using a one-sided independent samples t-test.
Maximum pain scores during insufflation were lower with alfentanil as compared with placebo, 5.3 versus 3.0 (P < 0.001). Total CT colonography pain and burden were also lower with alfentanil (2.0 vs. 1.6; P = 0.014 and 2.1 vs. 1.7; P = 0.007, respectively). With alfentanil fewer patients rated the insufflation as most burdensome aspect (56.1% vs. 18.6%; P = 0.001). Episodes with desaturations < 90% SpO2 were more common with alfentanil (8.1% vs. 44.4%; P < 0.001, but no clinically relevant desaturations occurred.
A low-dose intravenous alfentanil bolus provides a clinically relevant reduction of maximum pain during CT colonography and may improve the CT colonography acceptance, especially for patients with a low pain threshold.
Dutch Trial Register: NTR2902